Low oil pressure?

brian6pac said

A'm I looking at this right, I think I need to get my degree wheel out and assemble 1 piston and rod but you want 70* of the rod and crank not necessarily 70* ATDC because the rod is not straight up and down it's also at a angle, so 20* before the crank and rod are at 90*.

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I might be wrong Brian but I believe it is 70 atdc crank position.
I believe the theory goes that we might ignite the fuel mixture at say 35deg btdc, the burning mixture produces its maximum downward pressure on the rod journals at 70degrees atdc. This is deemed the ideal time to introduce a full pressure full flow gush of oil to get hydro dynamic wedge under the rod bearings.
Because the oiling hole location is different in a sbm versus a sbc the timing is not ideal.
Perhaps yellow rose will chime in here and correct me if I am wrong.